The present invention relates generally to a method of identifying, characterizing, and mapping seismic noise as an aid in evaluating and enhancing seismic data.
In seismic exploration, seismic noise is an unwanted phenomenon which detracts from the quality, and hence interpretability, of seismic data of interest. Seismic noise exists in two forms, coherent and incoherent seismic noise. Incoherent seismic noise is composed of many frequencies having random phase as contrasted by coherent seismic noise which exhibits a correlation in phase between separate seismic signals.
One type of coherent seismic noise is surface seismic noise. Surface seismic noise takes two principal forms. The first is background or cultural noise. Sources of cultural noise are road traffic, electric power lines, wind or wave noise and the like. Another source of surface seismic noise comes from what are termed scatterers. These are inhomogeneities in the earth's surface or near-surface materials in the area of the seismic survey which cause seismic energy, imparted by a seismic source, to be reflected or refracted in such a fashion as to be recorded in the seismic data. Both forms of surface seismic noise are unwanted because they do not contain information meaningful to the understanding of the earth's subsurface formations. Surface seismic noise can also interfere with or mask interpretation of seismic signals of interest.